LAGOS, Nigeria – Police say they discovered 12 corpses in a village in Nigeria's oil-rich southern delta, the same day they rescued an abducted Romanian and six others kidnapped in the restive region.

Rivers state police commissioner Suleiman Abba told The Associated Press on Friday the corpses were found in the village of Uni Ikata. Abba said police were working to determine the cause of death for 12 and had no information about communal clashes or violence in the area.

Meanwhile, Abba said a joint police, military and secret police group rescued the kidnap victims in an operation in the state. He said all were in good health.

Kidnappings for ransom remain common in Nigeria's oil-rich Niger Delta, where foreign oil workers, construction companies and middle-class Nigerians all are targets.